All the component projects of the Dartmouth SBRP engage in statistical analysis and scientific data management. The overall objective of the proposed Biostatistics and Data Management Core is to enhance program interactivity and scientific quality by providing the SBRP full access to the biostatistical expertise and data management resources at Dartmouth. The proposed projects involve in vitro and whole animal experimental protocols utilizing a number of complex and novel complex and novel bioassays (Project 1-3, Core A); population-based epidemiologic data with sophisticated biomarker measures of individual exposure and genetic markers (Project 4); and multi-level clustered sampling in ecological and geochemical surveys (Projects 6 and 7). Sound statistical methodology and data management are essential for the successful conduct of these projects. Economics of scale are achieved by sharing the support of statistical personnel, specialized software, and computing resources within the Core. In this way, projects that would not be able ordinarily to justify FTE lines for statistical personnel can still count on expert statistical resources during critical phases of the design and analysis of their experiments and studies. The Core will also develop enhanced statistical methods necessary to study the relationship between low to moderate arsenic exposures and cancer based on the use of multiple biomarkers of exposure, and will make use of unique Web-based statistical software maintained on the Core server (http://biostat.hitchcock.org/sbrp.htm).